[U-Boot] [PATCH v3] common/image.c: align usage of fdt_high with initrd_high

[Shawn Guo]

Gentle ping?

Regards,
Shawn

On Tue, Jan 10, 2012 at 03:54:08PM +0800, Shawn Guo wrote:
> The commit message of a28afca (Add uboot "fdt_high" enviroment variable)
> states that fdt_high behaves similarly to the existing initrd_high.
> But fdt_high actually has an outstanding difference from initrd_high.
> The former specifies the start address, while the later specifies the
> end address.
> 
> As fdt_high and initrd_high will likely be used together, it'd be nice
> to have them behave same.  The patch changes the behavior of fdt_high
> to have it aligned with initrd_high.
> 
> The document of fdt_high in README is updated with an example to
> demonstrate the usage of this environment variable.
> 
> Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
> ---
> Changes since v3:
>  * Fix the bug in case fdt_high=0xffffffff introduced by v1/v2.
> 
>  README         |    8 ++++++++
>  common/image.c |   12 +++++-------
>  2 files changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/README b/README
> index ff72e47..1c3713c 100644
> --- a/README
> +++ b/README
> @@ -3619,6 +3619,14 @@ List of environment variables (most likely not complete):
>  
>    fdt_high	- if set this restricts the maximum address that the
>  		  flattened device tree will be copied into upon boot.
> +		  For example, if you have a system with 1 GB memory
> +		  at physical address 0x10000000, while Linux kernel
> +		  only recognizes the first 704 MB as low memory, you
> +		  may need to set fdt_high as 0x3C000000 to have the
> +		  device tree blob be copied to the maximum address
> +		  of the 704 MB low memory, so that Linux kernel can
> +		  access it during the boot procedure.
> +
>  		  If this is set to the special value 0xFFFFFFFF then
>  		  the fdt will not be copied at all on boot.  For this
>  		  to work it must reside in writable memory, have
> diff --git a/common/image.c b/common/image.c
> index 77ca6e4..8c4137c 100644
> --- a/common/image.c
> +++ b/common/image.c
> @@ -1288,16 +1288,14 @@ int boot_relocate_fdt(struct lmb *lmb, char **of_flat_tree, ulong *of_size)
>  
>  		if (((ulong) desired_addr) == ~0UL) {
>  			/* All ones means use fdt in place */
> -			desired_addr = fdt_blob;
> +			of_start = fdt_blob;
> +			lmb_reserve(lmb, (ulong)of_start, of_len);
>  			disable_relocation = 1;
> -		}
> -		if (desired_addr) {
> +		} else if (desired_addr) {
>  			of_start =
>  			    (void *)(ulong) lmb_alloc_base(lmb, of_len, 0x1000,
> -							   ((ulong)
> -							    desired_addr)
> -							   + of_len);
> -			if (desired_addr && of_start != desired_addr) {
> +							   (ulong)desired_addr);
> +			if (of_start == 0) {
>  				puts("Failed using fdt_high value for Device Tree");
>  				goto error;
>  			}
> -- 
> 1.7.4.1
>